The design, synthesis and nonlinear optical properties of a novel, Y-type polyurethane containing tricyanovinylthiophene of high thermal stability

A novel, Y-type polyurethane containing 1-(2,4-dioxyethoxy)phenyl-2-{5-(2,2-dicyanovinyl)-2-thiophenyl}ethenes as nonlinear optical chromophores present within the polymer backbone, was prepared and characterized. The compound was soluble in common organic solvents and displayed thermal stability up to 260 °C and a glass transition temperature (Tg) of 163 °C. The second harmonic generation coefficient (d33) of poled polymer films at the compound's fundamental wavelength of 1560 nm was ∼3.72 × 10−9 esu. Dipole alignment exhibited high thermal stability up to the Tg, and there was no decay in d33 below 148 °C owing to the partial main-chain character of the polymer structure.